Add the option to specify the directory for output files
A few fixes to using an external build_dir

* Copy .hpp and .hh files
* Search for headers recursively
* Don't do anything except for cython sources
copy sources and depends instead of headers
Show attribute access and binary operations in default values in autogenerated signatures.
Attribute docstrings support for cdef public attributes.
Changed bint representation in autodoc signatures from 'int' to 'bool'.
Test fixes for autodoc improvements.
Merge pull request #214 from robertwb/T808

T808
Merge pull request #215 from robertwb/depends

Resolve depends attribute with respect to include_dirs.
minor code cleanups
prepare release of 0.19
Added tag 0.19rc1 for changeset 4818f5b68eb4
Added tag 0.19 for changeset 48407fa3f3c9
changelog
minor code cleanup
always convert C integer values to 1/0 when testing them for their boolean value
fix compiler crash
improve constant folding for boolean expressions (and/or)
fix switch transform after changing boolean coercion of integer expressions
fix test result reporting